The use of cosmetic preparations in stick form is well known. These preparations have varied from stick-type deodorants and antiperspirants to lipsticks to compressed cosmetic powder sticks. Depending upon the specific application, the vehicle employed in a stick-type cosmetic can vary greatly.
For example, stick-type deodorant compositions typically consist of a bacteriostat or other biologically active compound dispersed in a vehicle comprising an alcohol-based gel containing either ethanol or a glycol such as propylene glycol, as the vehicle base. In either case, gelation is effected by use of a soap, e.g., sodium stearate, as the gelling agent. These stick-type deodorants may also contain small amounts of other additives, such as perfumes, humectants, various surfactants, dyes or other colorants, water, etc. Both types of formulation have left something to be desired. For example, the ethanol in the ethanol-based product is relatively volatile and can evaporate on storage, especially at elevated temperatures. As a consequence, the stick shrinks and becomes mis-shapen and generally useless. The glycol-based deodorant sticks do not suffer from this disadvantage; however, glycols provide a product which is hard and waxy, and thus has an undesirable "feel" and/or little covering power.
Lipsticks and similar cosmetic products, on the other hand, typically employ fats and/or waxes, such as castor oil, carnauba wax, candelia wax, beeswax, and the like. Vehicles of this type are relatively expensive, and in many cases cannot be employed in the formulation of other cosmetic products.
Powder sticks have been formed by compression of the powder; however, such products are generally so hard that it is difficult to deposit sufficient powder when the compressed powder is applied to the skin of the user. As a consequence, various solutions have been proposed, such as reducing the degree of compression, coupled with providing the composition with a separate wrapper or a dry film to prevent "shedding" of the loosely compacted powder. See, e.g., U.S. Pat. No. 3,471,611. In another effort, the use of gums or other materials as adhesive binders have been described in U.S. Pat. No. 3,800,034. Such efforts have not been particularly successful, and by increasing the number of manufacturing steps, necessarily increase cost of manufacture of the product.